What are the different dream levels for the final mission?

Level 1: the one with the van, dreamed by Yusuf, "The Chemist"Level 2: the one in the hotel, dreamed by Arthur, "The Point Man"Level 3: the one in the snow, dreamed by Eames, "The Forger"Level 4: the one in the crumbling city, dreamed by Cobb, "The Extractor"

All level's subject is Fischer "The Mark", whom they want to perform the inception to.

In every level, Fischer's projections are attacking the foreign dreamer because he is influencing his dreams.

Remember that Cobb explains to Ariadne that in his dream, when she makes changes, his subconscious notices that these changes are coming from an outside source and this causes increasing hostility from the dreamer. All the dream levels are Fischer's. In every level, Fischer's projections are attacking the foreign dreamers because they are influencing his dreams. It may appear to be Yusuf's on the first level because he has to pee and this causes there to be a rainstorm. However, it is his influence that having to pee affects the dream because he is sharing it with the others. Further examples: Arthur and Ariadne in the hotel are being scrutinized as they sit on a bench. Arthur then uses this opportunity to kiss Ariadne as a pretext to distract the projections. In every level, the main characters are being attacked by projections, but they are all a part of Fischer's mind.

There is clearly at least one more level because the totem is still spinning at the end of the movie, after they are kicked out of the "van" dream. Therefore the whole part involving the airplane is another level, although it is not clear who it is dreamed by

From level 1 to 3, I agree all is Fischer's dream. But when it come to the level, it couldn't be as Fischer woke up earlier than all the others, Ariadna, Saito and Cobb, and bounce back to level 3. That would end up 3 of them are left in limbo. Follow this logic, Ariadne and Fischer can't be the dreamer.
Come to choose between Cobb and Saito, which I can't make any as if it was Cobb the dreamer which wouldn't happen that he fully consious about his dream (his projections won't allow that) and neither was Saito as seems he was not connecting to the dream-suitcase.
Well, without any choice left, I would come back to original that Fischer the dreamer of Level 4 and accept it was a flaw in the screenplay that Fischer wake up earlier than the others.

Level 4: the one in the crumbling city, dreamed by Cobb, the Extractor

OR (alternative explanation of Level 4) Limbo, a level shared by several dreamers.

Alternative Answer:

They are all levels of Fischer's subconscious, going deeper each time. Dream architects, such as Ariadne and Cobb, can change the dream layout. Ariadne constructs the first three levels, the city, the hotel, the mountain fortress, while they reluctantly follow down into limbo - Cobb's construction of an entire city which leaves Ariadne in awe. It is decayed and crumbling away from abandonment. Eventually Cobb find Saito, who has filled up limbo with his own fortress and aged, just as Cobb did, which they both mention.

The more architects change the dream world of someone else, however, the more they attract attention from projections, who see the architects as invaders as is the case in the film with Fischer's projections.

Detail on my additions: it is important to remember that each level needs three positions filled (1) Designer, who builds the dream; (2) Dreamer, who learns the design and recreates it as a dream; (3) Populator, who's unconscious is projected into the dream space. These roles can be filled by separate people, or the same person. In normal sleep, the dreamer fills all three roles. Fischer populates Levels 1-3, but he does not dream them (in the sense used here).

Notes against Fischer as dreamer on Level 3:
(1) The dreamer who is dreaming a level cannot move to a level below (or they wouldn't be dreaming that level any more), therefor at each level a dreamer must be left behind to dream the next level's dream. On Level 1 this is Yusuf, on Level 2 this is Arthur. As Fischer appears in both level 3 and 4, he cannot be dreaming level 3.
(2) Eames remains behind, he does not enter Level 4 with Cobb, Ariadne and Fischer.
(3) The dreamer has Edith Piaf played through headphones just before the "kick". As the dreamer is generating the next level the sound of Edith Piaf is heard by all characters on that level (just as water felt on one level seeps through into the next).
(4) Eames has headphones placed on him in Level 2, and the music is heard by those in Level 3.
(5) Fischer must populate Level 3, it is his unconscious they are trying to incept, but he does not have to dream it, in the technical sense.

Level 4: the one in the crumbling city, dreamed by Cobb, "The Extractor"

OR (alternative explanation of Level 4) Limbo, a level shared by several dreamers.OR (alternative explanation of Level 3) dreamed by Eames, "The Forger"; populated by Fischer.

Levels 1-3 are designed by Ariadne, "The Architect". Level 4 is designed by Cobb, The Extractor, likely based on his memory of limbo (which, in turn, was designed by Mal "The Shade" and Cobb, based on their memory of reality).

Level 4: the one in the crumbling city, dreamed by Cobb, "The Extractor"

OR (alternative explanation of Level 4) Limbo, a level shared by several dreamers.OR (alternative explanation of Level 3) dreamed by Eames, "The Forger"; populated by Fischer.

DESIGNERS

Levels 1-3 are designed by Ariadne, "The Architect". Level 4 is designed by Cobb, The Extractor, likely based on his memory of limbo (which, in turn, was designed by Mal "The Shade" and Cobb, based on their memory of reality).

POPULATION

Levels 1-3 are populated by Fischer's unconscious (with the occasional intrusion from Cobb's unconsious).Level 4 is populated by Cobb's unconscious.

Level 1: the one with the van, dreamed by Yusuf, "The Chemist"
Level 2: the one in the hotel, dreamed by Arthur, "The Point Man"
Level 3: the one in the snow, dreamed by Eames, "The Forger"
Level 4: the one in the crumbling city, dreamed by Cobb, "The Extractor"

All level's subject is Fischer "The Mark", whom they want to perform the inception to.

In every level, Fischer's projections are attacking the foreign dreamers because they are influencing his dreams.

Level 1: the one with the van, dreamed by Yusuf, "The Chemist"Level 2: the one in the hotel, dreamed by Arthur, "The Point Man"Level 3: the one in the snow, dreamed by Eames, "The Forger"Level 4: the one in the crumbling city, dreamed by Cobb, "The Extractor"

All level's subject is Fischer "The Mark", whom they want to perform the inception to.

In every level, Fischer's projections are attacking the foreign dreamer because he is influencing his dreams.